print("Please input a score, and I'll give it a grade.")

score = float(input('Score: '))

if score < 0:
    print("That's not a proper score.")
elif score < 60:
    print('E')
elif score < 70:
    print('D')
elif score < 80:
    print('C')
elif score < 90:
    print('B')
elif score < 100:
    print('A')
else:
    print("The score should be less than 100.")
